title: Long-term follow-up of patients with papillary and follicular thyroid cancer: a prospective study on 715 patients.
abstract: OBJECTIVE
  This prospective study evaluated the recurrence rate in 715 patients with differentiated thyroid cancer who had no evidence of persistent disease after total thyroidectomy and lymph node dissection in 94% of them followed up by radioiodine ablation (30-100 mCi) and assessed the predictive value of the initial thyroglobulin (Tg) levels for detecting recurrence, both during levothyroxine (LT4) treatment and after TSH stimulation.
  
  
  METHODS
  Patients had Tg determinations performed at 3 months on LT4 treatment (Tg1) and at 9-12 months after stimulation by either thyroid hormone withdrawal or recombinant human TSH (Tg2); the Access kit was used (functional sensitivity of 0.11 ng/ml); they had undetectable anti-Tg antibodies. Patients were followed up annually. Predictive values were calculated by comparing Tg levels (Tg1 and Tg2) and the outcome in terms of recurrence.
  
  
  RESULTS
  During the median follow-up of 6.2 yr, 32 patients had a recurrence. Assuming a cutoff level for Tg1 at 0.27 ng/ml, Tg1 sensitivity and specificity reached 72 and 86%, respectively, whereas predictive positive and negative values were 20 and 99%, respectively. With a cutoff level for Tg2 at 1.4 ng/ml, sensitivity and specificity reached 78 and 90%, respectively, whereas positive and negative predictive values were 26 and 99%, respectively.
  
  
  CONCLUSIONS
  This large prospective cohort of patients presented a low rate of recurrence. Initial Tg measurements allow to predict long-term recurrence with an excellent specificity. Stimulated Tg determination presented a slightly higher sensitivity than Tg determination on LT4. TSH stimulation may be avoided when Tg measured 3 months after ablation is less than 0.27 ng/ml during LT4 treatment.
authors.affiliation: Department of Nuclear Medicine and Endocrine Oncology, Institut Gustave Roussy, 94805 Villejuif, France. maryse.brassard@usherbrooke.ca
authors.forename: M
authors.initials: M
authors.lastname: Brassard
authors.forename: I
authors.initials: I
authors.lastname: Borget
authors.forename: A
authors.initials: A
authors.lastname: Edet-Sanson
authors.forename: A-L
authors.initials: AL
authors.lastname: Giraudet
authors.forename: O
authors.initials: O
authors.lastname: Mundler
authors.forename: M
authors.initials: M
authors.lastname: Toubeau
authors.forename: F
authors.initials: F
authors.lastname: Bonichon
authors.forename: F
authors.initials: F
authors.lastname: Borson-Chazot
authors.forename: L
authors.initials: L
authors.lastname: Leenhardt
authors.forename: C
authors.initials: C
authors.lastname: Schvartz
authors.forename: C
authors.initials: C
authors.lastname: Dejax
authors.forename: I
authors.initials: I
authors.lastname: Brenot-Rossi
authors.forename: M-E
authors.initials: ME
authors.lastname: Toubert
authors.forename: M
authors.initials: M
authors.lastname: Torlontano
authors.forename: E
authors.initials: E
authors.lastname: Benhamou
authors.forename: M
authors.initials: M
authors.lastname: Schlumberger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000032:analysis; D018265:Carcinoma, Papillary, Follicular / Q000453:epidemiology / Q000601:surgery / Q000628:therapy*; D015331:Cohort Studies; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D020249:Hormone Replacement Therapy; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008197:Lymph Node Excision; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013954:Thyroglobulin / Q000276:immunology; D013964:Thyroid Neoplasms / Q000453:epidemiology / Q000601:surgery*; D013965:Thyroidectomy; D013972:Thyrotropin / Q000627:therapeutic use; D013974:Thyroxine / Q000627:therapeutic use; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D007457:Iodine Radioisotopes; D013972:Thyrotropin; D013954:Thyroglobulin; D013974:Thyroxine